import pandas as pd

df1 = pd.DataFrame(
    [{"r1": 'a', "r2": 1, "symbol": "s1"},
     {"r1": "b", "r2": 2, "symbol": "s2"},
     {"r1": "c", "r2": 2, "symbol": "s3"},
     {"r1": "a", "r2": 3, "symbol": "s4"}
     ]
)
df2 = df1.append({"r1": "aa", "r2": 33, "r3": "xxx"}, ignore_index=True)
print(df2)

df3 = pd.DataFrame()
df3.append({"r1": "aa", "r2": 33, "r3": "xxx"}, ignore_index=True)
print(df3)
df3 = df3.append({"r1": "aa", "r2": 33, "r3": "xxx"}, ignore_index=True)
print(df3)

list1 = [{"r1": "aa", "r2": 33, "r3": "xxx"}, {"r1": 'a', "r2": 1, "symbol": "s1"}]
